1. Field of the Invention
The invention relates to an image display apparatus.
2. Related Background Art
Hitherto, two kinds of sources such as thermionic electron source and cold cathode electron source have been known as electron-emitting devices. As cold cathode electron sources, there are a field emission device (hereinbelow, abbreviated to an “FE type device”), a metal/insulating layer/metal type device (hereinbelow, abbreviated to an “MIM device”), a surface conduction electron-emitting device (hereinbelow, abbreviated to an “SCE device”), and the like.
An image display apparatus in which a number of electron-emitting devices mentioned above are arranged on a substrate and used as an electron source has also been proposed.
Generally, such a kind of image display apparatus has a structure in which a rear plate on which a plurality of electron-emitting devices are arranged in a matrix and a face plate on which phosphor is provided so as to face each of the plurality of electron-emitting devices are arranged so as to face each other. According to such an image display apparatus, by applying a high voltage between the rear plate and the face plate, electrons emitted from the electron-emitting devices collide with phosphor and phosphor emits light. In this instance, by controlling the electron emission from each electron-emitting device, the light emission in each phosphor is controlled, so that an image is displayed.
With respect to a technique regarding the SCE device mentioned above, a part of the prior arts by the same applicant as the present invention will be introduced hereinbelow for reference.
For instance, as examples of the electron source in which the SCE devices are arranged in a matrix and an image display apparatus using such an electron source, Japanese Patent Application Laid-Open No. H08-185818, Japanese Patent Application Laid-Open No. H09-050757, and the like can be mentioned.
FIGS. 9A and 9B show an electron-emitting device (SCE device) used in an image forming apparatus. 91 denotes a substrate. 92 and 93 denote device electrodes having a width W and being spaced form each other by a gap L. 94 denotes an electroconductive film. 95 denotes an electron emitting portion constituted by a fissure formed in the electrodonductive film 94.
According to the conventional image display apparatus using the electron-emitting devices, there is a case where a discharge occurs in the apparatus. When such a discharge occurs, there is a case where The electron-emitting device is damaged. When such a damage occurs in a number of electron-emitting devices, consequently, there is also a fear that a life of the image display apparatus itself is consequently shortened.